terraform/terraform/eval_diff.go

804 lines
28 KiB
Go

package terraform
import (
"fmt"
"log"
"strings"
"github.com/hashicorp/hcl/v2"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/configs"
"github.com/hashicorp/terraform/plans"
"github.com/hashicorp/terraform/plans/objchange"
"github.com/hashicorp/terraform/providers"
"github.com/hashicorp/terraform/states"
"github.com/hashicorp/terraform/tfdiags"
)
// EvalCheckPlannedChange is an EvalNode implementation that produces errors
// if the _actual_ expected value is not compatible with what was recorded
// in the plan.
//
// Errors here are most often indicative of a bug in the provider, so our
// error messages will report with that in mind. It's also possible that
// there's a bug in Terraform's Core's own "proposed new value" code in
// EvalDiff.
type EvalCheckPlannedChange struct {
Addr addrs.ResourceInstance
ProviderAddr addrs.AbsProviderConfig
ProviderSchema **ProviderSchema
// We take ResourceInstanceChange objects here just because that's what's
// convenient to pass in from the evaltree implementation, but we really
// only look at the "After" value of each change.
Planned, Actual **plans.ResourceInstanceChange
}
func (n *EvalCheckPlannedChange) Eval(ctx EvalContext) (interface{}, error) {
providerSchema := *n.ProviderSchema
plannedChange := *n.Planned
actualChange := *n.Actual
schema, _ := providerSchema.SchemaForResourceAddr(n.Addr.ContainingResource())
if schema == nil {
// Should be caught during validation, so we don't bother with a pretty error here
return nil, fmt.Errorf("provider does not support %q", n.Addr.Resource.Type)
}
var diags tfdiags.Diagnostics
absAddr := n.Addr.Absolute(ctx.Path())
log.Printf("[TRACE] EvalCheckPlannedChange: Verifying that actual change (action %s) matches planned change (action %s)", actualChange.Action, plannedChange.Action)
if plannedChange.Action != actualChange.Action {
switch {
case plannedChange.Action == plans.Update && actualChange.Action == plans.NoOp:
// It's okay for an update to become a NoOp once we've filled in
// all of the unknown values, since the final values might actually
// match what was there before after all.
log.Printf("[DEBUG] After incorporating new values learned so far during apply, %s change has become NoOp", absAddr)
default:
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Provider produced inconsistent final plan",
fmt.Sprintf(
"When expanding the plan for %s to include new values learned so far during apply, provider %q changed the planned action from %s to %s.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
absAddr, n.ProviderAddr.ProviderConfig.Type,
plannedChange.Action, actualChange.Action,
),
))
}
}
errs := objchange.AssertObjectCompatible(schema, plannedChange.After, actualChange.After)
for _, err := range errs {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Provider produced inconsistent final plan",
fmt.Sprintf(
"When expanding the plan for %s to include new values learned so far during apply, provider %q produced an invalid new value for %s.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
absAddr, n.ProviderAddr.ProviderConfig.Type, tfdiags.FormatError(err),
),
))
}
return nil, diags.Err()
}
// EvalDiff is an EvalNode implementation that detects changes for a given
// resource instance.
type EvalDiff struct {
Addr addrs.ResourceInstance
Config *configs.Resource
Provider *providers.Interface
ProviderAddr addrs.AbsProviderConfig
ProviderSchema **ProviderSchema
State **states.ResourceInstanceObject
PreviousDiff **plans.ResourceInstanceChange
// CreateBeforeDestroy is set if either the resource's own config sets
// create_before_destroy explicitly or if dependencies have forced the
// resource to be handled as create_before_destroy in order to avoid
// a dependency cycle.
CreateBeforeDestroy bool
OutputChange **plans.ResourceInstanceChange
OutputValue *cty.Value
OutputState **states.ResourceInstanceObject
Stub bool
}
// TODO: test
func (n *EvalDiff) Eval(ctx EvalContext) (interface{}, error) {
state := *n.State
config := *n.Config
provider := *n.Provider
providerSchema := *n.ProviderSchema
if providerSchema == nil {
return nil, fmt.Errorf("provider schema is unavailable for %s", n.Addr)
}
if n.ProviderAddr.ProviderConfig.Type.LegacyString() == "" {
panic(fmt.Sprintf("EvalDiff for %s does not have ProviderAddr set", n.Addr.Absolute(ctx.Path())))
}
var diags tfdiags.Diagnostics
// Evaluate the configuration
schema, _ := providerSchema.SchemaForResourceAddr(n.Addr.ContainingResource())
if schema == nil {
// Should be caught during validation, so we don't bother with a pretty error here
return nil, fmt.Errorf("provider does not support resource type %q", n.Addr.Resource.Type)
}
forEach, _ := evaluateResourceForEachExpression(n.Config.ForEach, ctx)
keyData := EvalDataForInstanceKey(n.Addr.Key, forEach)
configVal, _, configDiags := ctx.EvaluateBlock(config.Config, schema, nil, keyData)
diags = diags.Append(configDiags)
if configDiags.HasErrors() {
return nil, diags.Err()
}
absAddr := n.Addr.Absolute(ctx.Path())
var priorVal cty.Value
var priorValTainted cty.Value
var priorPrivate []byte
if state != nil {
if state.Status != states.ObjectTainted {
priorVal = state.Value
priorPrivate = state.Private
} else {
// If the prior state is tainted then we'll proceed below like
// we're creating an entirely new object, but then turn it into
// a synthetic "Replace" change at the end, creating the same
// result as if the provider had marked at least one argument
// change as "requires replacement".
priorValTainted = state.Value
priorVal = cty.NullVal(schema.ImpliedType())
}
} else {
priorVal = cty.NullVal(schema.ImpliedType())
}
proposedNewVal := objchange.ProposedNewObject(schema, priorVal, configVal)
// Call pre-diff hook
if !n.Stub {
err := ctx.Hook(func(h Hook) (HookAction, error) {
return h.PreDiff(absAddr, states.CurrentGen, priorVal, proposedNewVal)
})
if err != nil {
return nil, err
}
}
log.Printf("[TRACE] Re-validating config for %q", n.Addr.Absolute(ctx.Path()))
// Allow the provider to validate the final set of values.
// The config was statically validated early on, but there may have been
// unknown values which the provider could not validate at the time.
validateResp := provider.ValidateResourceTypeConfig(
providers.ValidateResourceTypeConfigRequest{
TypeName: n.Addr.Resource.Type,
Config: configVal,
},
)
if validateResp.Diagnostics.HasErrors() {
return nil, validateResp.Diagnostics.InConfigBody(config.Config).Err()
}
// The provider gets an opportunity to customize the proposed new value,
// which in turn produces the _planned_ new value. But before
// we send back this information, we need to process ignore_changes
// so that CustomizeDiff will not act on them
var ignoreChangeDiags tfdiags.Diagnostics
proposedNewVal, ignoreChangeDiags = n.processIgnoreChanges(priorVal, proposedNewVal)
diags = diags.Append(ignoreChangeDiags)
if ignoreChangeDiags.HasErrors() {
return nil, diags.Err()
}
resp := provider.PlanResourceChange(providers.PlanResourceChangeRequest{
TypeName: n.Addr.Resource.Type,
Config: configVal,
PriorState: priorVal,
ProposedNewState: proposedNewVal,
PriorPrivate: priorPrivate,
})
diags = diags.Append(resp.Diagnostics.InConfigBody(config.Config))
if diags.HasErrors() {
return nil, diags.Err()
}
plannedNewVal := resp.PlannedState
plannedPrivate := resp.PlannedPrivate
if plannedNewVal == cty.NilVal {
// Should never happen. Since real-world providers return via RPC a nil
// is always a bug in the client-side stub. This is more likely caused
// by an incompletely-configured mock provider in tests, though.
panic(fmt.Sprintf("PlanResourceChange of %s produced nil value", absAddr.String()))
}
// We allow the planned new value to disagree with configuration _values_
// here, since that allows the provider to do special logic like a
// DiffSuppressFunc, but we still require that the provider produces
// a value whose type conforms to the schema.
for _, err := range plannedNewVal.Type().TestConformance(schema.ImpliedType()) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Provider produced invalid plan",
fmt.Sprintf(
"Provider %q planned an invalid value for %s.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
n.ProviderAddr.ProviderConfig.Type, tfdiags.FormatErrorPrefixed(err, absAddr.String()),
),
))
}
if diags.HasErrors() {
return nil, diags.Err()
}
if errs := objchange.AssertPlanValid(schema, priorVal, configVal, plannedNewVal); len(errs) > 0 {
if resp.LegacyTypeSystem {
// The shimming of the old type system in the legacy SDK is not precise
// enough to pass this consistency check, so we'll give it a pass here,
// but we will generate a warning about it so that we are more likely
// to notice in the logs if an inconsistency beyond the type system
// leads to a downstream provider failure.
var buf strings.Builder
fmt.Fprintf(&buf, "[WARN] Provider %q produced an invalid plan for %s, but we are tolerating it because it is using the legacy plugin SDK.\n The following problems may be the cause of any confusing errors from downstream operations:", n.ProviderAddr.ProviderConfig.Type, absAddr)
for _, err := range errs {
fmt.Fprintf(&buf, "\n - %s", tfdiags.FormatError(err))
}
log.Print(buf.String())
} else {
for _, err := range errs {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Provider produced invalid plan",
fmt.Sprintf(
"Provider %q planned an invalid value for %s.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
n.ProviderAddr.ProviderConfig.Type, tfdiags.FormatErrorPrefixed(err, absAddr.String()),
),
))
}
return nil, diags.Err()
}
}
// TODO: We should be able to remove this repeat of processing ignored changes
// after the plan, which helps providers relying on old behavior "just work"
// in the next major version, such that we can be stricter about ignore_changes
// values
plannedNewVal, ignoreChangeDiags = n.processIgnoreChanges(priorVal, plannedNewVal)
diags = diags.Append(ignoreChangeDiags)
if ignoreChangeDiags.HasErrors() {
return nil, diags.Err()
}
// The provider produces a list of paths to attributes whose changes mean
// that we must replace rather than update an existing remote object.
// However, we only need to do that if the identified attributes _have_
// actually changed -- particularly after we may have undone some of the
// changes in processIgnoreChanges -- so now we'll filter that list to
// include only where changes are detected.
reqRep := cty.NewPathSet()
if len(resp.RequiresReplace) > 0 {
for _, path := range resp.RequiresReplace {
if priorVal.IsNull() {
// If prior is null then we don't expect any RequiresReplace at all,
// because this is a Create action.
continue
}
priorChangedVal, priorPathDiags := hcl.ApplyPath(priorVal, path, nil)
plannedChangedVal, plannedPathDiags := hcl.ApplyPath(plannedNewVal, path, nil)
if plannedPathDiags.HasErrors() && priorPathDiags.HasErrors() {
// This means the path was invalid in both the prior and new
// values, which is an error with the provider itself.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Provider produced invalid plan",
fmt.Sprintf(
"Provider %q has indicated \"requires replacement\" on %s for a non-existent attribute path %#v.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
n.ProviderAddr.ProviderConfig.Type, absAddr, path,
),
))
continue
}
// Make sure we have valid Values for both values.
// Note: if the opposing value was of the type
// cty.DynamicPseudoType, the type assigned here may not exactly
// match the schema. This is fine here, since we're only going to
// check for equality, but if the NullVal is to be used, we need to
// check the schema for th true type.
switch {
case priorChangedVal == cty.NilVal && plannedChangedVal == cty.NilVal:
// this should never happen without ApplyPath errors above
panic("requires replace path returned 2 nil values")
case priorChangedVal == cty.NilVal:
priorChangedVal = cty.NullVal(plannedChangedVal.Type())
case plannedChangedVal == cty.NilVal:
plannedChangedVal = cty.NullVal(priorChangedVal.Type())
}
eqV := plannedChangedVal.Equals(priorChangedVal)
if !eqV.IsKnown() || eqV.False() {
reqRep.Add(path)
}
}
if diags.HasErrors() {
return nil, diags.Err()
}
}
eqV := plannedNewVal.Equals(priorVal)
eq := eqV.IsKnown() && eqV.True()
var action plans.Action
switch {
case priorVal.IsNull():
action = plans.Create
case eq:
action = plans.NoOp
case !reqRep.Empty():
// If there are any "requires replace" paths left _after our filtering
// above_ then this is a replace action.
if n.CreateBeforeDestroy {
action = plans.CreateThenDelete
} else {
action = plans.DeleteThenCreate
}
default:
action = plans.Update
// "Delete" is never chosen here, because deletion plans are always
// created more directly elsewhere, such as in "orphan" handling.
}
if action.IsReplace() {
// In this strange situation we want to produce a change object that
// shows our real prior object but has a _new_ object that is built
// from a null prior object, since we're going to delete the one
// that has all the computed values on it.
//
// Therefore we'll ask the provider to plan again here, giving it
// a null object for the prior, and then we'll meld that with the
// _actual_ prior state to produce a correctly-shaped replace change.
// The resulting change should show any computed attributes changing
// from known prior values to unknown values, unless the provider is
// able to predict new values for any of these computed attributes.
nullPriorVal := cty.NullVal(schema.ImpliedType())
// create a new proposed value from the null state and the config
proposedNewVal = objchange.ProposedNewObject(schema, nullPriorVal, configVal)
resp = provider.PlanResourceChange(providers.PlanResourceChangeRequest{
TypeName: n.Addr.Resource.Type,
Config: configVal,
PriorState: nullPriorVal,
ProposedNewState: proposedNewVal,
PriorPrivate: plannedPrivate,
})
// We need to tread carefully here, since if there are any warnings
// in here they probably also came out of our previous call to
// PlanResourceChange above, and so we don't want to repeat them.
// Consequently, we break from the usual pattern here and only
// append these new diagnostics if there's at least one error inside.
if resp.Diagnostics.HasErrors() {
diags = diags.Append(resp.Diagnostics.InConfigBody(config.Config))
return nil, diags.Err()
}
plannedNewVal = resp.PlannedState
plannedPrivate = resp.PlannedPrivate
for _, err := range plannedNewVal.Type().TestConformance(schema.ImpliedType()) {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Provider produced invalid plan",
fmt.Sprintf(
"Provider %q planned an invalid value for %s%s.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
n.ProviderAddr.ProviderConfig.Type, absAddr, tfdiags.FormatError(err),
),
))
}
if diags.HasErrors() {
return nil, diags.Err()
}
}
// If our prior value was tainted then we actually want this to appear
// as a replace change, even though so far we've been treating it as a
// create.
if action == plans.Create && priorValTainted != cty.NilVal {
if n.CreateBeforeDestroy {
action = plans.CreateThenDelete
} else {
action = plans.DeleteThenCreate
}
priorVal = priorValTainted
}
// As a special case, if we have a previous diff (presumably from the plan
// phases, whereas we're now in the apply phase) and it was for a replace,
// we've already deleted the original object from state by the time we
// get here and so we would've ended up with a _create_ action this time,
// which we now need to paper over to get a result consistent with what
// we originally intended.
if n.PreviousDiff != nil {
prevChange := *n.PreviousDiff
if prevChange.Action.IsReplace() && action == plans.Create {
log.Printf("[TRACE] EvalDiff: %s treating Create change as %s change to match with earlier plan", absAddr, prevChange.Action)
action = prevChange.Action
priorVal = prevChange.Before
}
}
// Call post-refresh hook
if !n.Stub {
err := ctx.Hook(func(h Hook) (HookAction, error) {
return h.PostDiff(absAddr, states.CurrentGen, action, priorVal, plannedNewVal)
})
if err != nil {
return nil, err
}
}
// Update our output if we care
if n.OutputChange != nil {
*n.OutputChange = &plans.ResourceInstanceChange{
Addr: absAddr,
Private: plannedPrivate,
ProviderAddr: n.ProviderAddr,
Change: plans.Change{
Action: action,
Before: priorVal,
After: plannedNewVal,
},
RequiredReplace: reqRep,
}
}
if n.OutputValue != nil {
*n.OutputValue = configVal
}
// Update the state if we care
if n.OutputState != nil {
*n.OutputState = &states.ResourceInstanceObject{
// We use the special "planned" status here to note that this
// object's value is not yet complete. Objects with this status
// cannot be used during expression evaluation, so the caller
// must _also_ record the returned change in the active plan,
// which the expression evaluator will use in preference to this
// incomplete value recorded in the state.
Status: states.ObjectPlanned,
Value: plannedNewVal,
Private: plannedPrivate,
}
}
return nil, nil
}
func (n *EvalDiff) processIgnoreChanges(prior, proposed cty.Value) (cty.Value, tfdiags.Diagnostics) {
// ignore_changes only applies when an object already exists, since we
// can't ignore changes to a thing we've not created yet.
if prior.IsNull() {
return proposed, nil
}
ignoreChanges := n.Config.Managed.IgnoreChanges
ignoreAll := n.Config.Managed.IgnoreAllChanges
if len(ignoreChanges) == 0 && !ignoreAll {
return proposed, nil
}
if ignoreAll {
return prior, nil
}
if prior.IsNull() || proposed.IsNull() {
// Ignore changes doesn't apply when we're creating for the first time.
// Proposed should never be null here, but if it is then we'll just let it be.
return proposed, nil
}
return processIgnoreChangesIndividual(prior, proposed, ignoreChanges)
}
func processIgnoreChangesIndividual(prior, proposed cty.Value, ignoreChanges []hcl.Traversal) (cty.Value, tfdiags.Diagnostics) {
// When we walk below we will be using cty.Path values for comparison, so
// we'll convert our traversals here so we can compare more easily.
ignoreChangesPath := make([]cty.Path, len(ignoreChanges))
for i, traversal := range ignoreChanges {
path := make(cty.Path, len(traversal))
for si, step := range traversal {
switch ts := step.(type) {
case hcl.TraverseRoot:
path[si] = cty.GetAttrStep{
Name: ts.Name,
}
case hcl.TraverseAttr:
path[si] = cty.GetAttrStep{
Name: ts.Name,
}
case hcl.TraverseIndex:
path[si] = cty.IndexStep{
Key: ts.Key,
}
default:
panic(fmt.Sprintf("unsupported traversal step %#v", step))
}
}
ignoreChangesPath[i] = path
}
var diags tfdiags.Diagnostics
ret, _ := cty.Transform(proposed, func(path cty.Path, v cty.Value) (cty.Value, error) {
// First we must see if this is a path that's being ignored at all.
// We're looking for an exact match here because this walk will visit
// leaf values first and then their containers, and we want to do
// the "ignore" transform once we reach the point indicated, throwing
// away any deeper values we already produced at that point.
var ignoreTraversal hcl.Traversal
for i, candidate := range ignoreChangesPath {
if path.Equals(candidate) {
ignoreTraversal = ignoreChanges[i]
}
}
if ignoreTraversal == nil {
return v, nil
}
// If we're able to follow the same path through the prior value,
// we'll take the value there instead, effectively undoing the
// change that was planned.
priorV, diags := hcl.ApplyPath(prior, path, nil)
if diags.HasErrors() {
// We just ignore the errors and move on here, since we assume it's
// just because the prior value was a slightly-different shape.
// It could potentially also be that the traversal doesn't match
// the schema, but we should've caught that during the validate
// walk if so.
return v, nil
}
return priorV, nil
})
return ret, diags
}
// a group of key-*ResourceAttrDiff pairs from the same flatmapped container
type flatAttrDiff map[string]*ResourceAttrDiff
// we need to keep all keys if any of them have a diff that's not ignored
func (f flatAttrDiff) keepDiff(ignoreChanges map[string]bool) bool {
for k, v := range f {
ignore := false
for attr := range ignoreChanges {
if strings.HasPrefix(k, attr) {
ignore = true
}
}
if !v.Empty() && !v.NewComputed && !ignore {
return true
}
}
return false
}
// EvalDiffDestroy is an EvalNode implementation that returns a plain
// destroy diff.
type EvalDiffDestroy struct {
Addr addrs.ResourceInstance
DeposedKey states.DeposedKey
State **states.ResourceInstanceObject
ProviderAddr addrs.AbsProviderConfig
Output **plans.ResourceInstanceChange
OutputState **states.ResourceInstanceObject
}
// TODO: test
func (n *EvalDiffDestroy) Eval(ctx EvalContext) (interface{}, error) {
absAddr := n.Addr.Absolute(ctx.Path())
state := *n.State
if n.ProviderAddr.ProviderConfig.Type.LegacyString() == "" {
if n.DeposedKey == "" {
panic(fmt.Sprintf("EvalDiffDestroy for %s does not have ProviderAddr set", absAddr))
} else {
panic(fmt.Sprintf("EvalDiffDestroy for %s (deposed %s) does not have ProviderAddr set", absAddr, n.DeposedKey))
}
}
// If there is no state or our attributes object is null then we're already
// destroyed.
if state == nil || state.Value.IsNull() {
return nil, nil
}
// Call pre-diff hook
err := ctx.Hook(func(h Hook) (HookAction, error) {
return h.PreDiff(
absAddr, n.DeposedKey.Generation(),
state.Value,
cty.NullVal(cty.DynamicPseudoType),
)
})
if err != nil {
return nil, err
}
// Change is always the same for a destroy. We don't need the provider's
// help for this one.
// TODO: Should we give the provider an opportunity to veto this?
change := &plans.ResourceInstanceChange{
Addr: absAddr,
DeposedKey: n.DeposedKey,
Change: plans.Change{
Action: plans.Delete,
Before: state.Value,
After: cty.NullVal(cty.DynamicPseudoType),
},
Private: state.Private,
ProviderAddr: n.ProviderAddr,
}
// Call post-diff hook
err = ctx.Hook(func(h Hook) (HookAction, error) {
return h.PostDiff(
absAddr,
n.DeposedKey.Generation(),
change.Action,
change.Before,
change.After,
)
})
if err != nil {
return nil, err
}
// Update our output
*n.Output = change
if n.OutputState != nil {
// Record our proposed new state, which is nil because we're destroying.
*n.OutputState = nil
}
return nil, nil
}
// EvalReduceDiff is an EvalNode implementation that takes a planned resource
// instance change as might be produced by EvalDiff or EvalDiffDestroy and
// "simplifies" it to a single atomic action to be performed by a specific
// graph node.
//
// Callers must specify whether they are a destroy node or a regular apply
// node. If the result is NoOp then the given change requires no action for
// the specific graph node calling this and so evaluation of the that graph
// node should exit early and take no action.
//
// The object written to OutChange may either be identical to InChange or
// a new change object derived from InChange. Because of the former case, the
// caller must not mutate the object returned in OutChange.
type EvalReduceDiff struct {
Addr addrs.ResourceInstance
InChange **plans.ResourceInstanceChange
Destroy bool
OutChange **plans.ResourceInstanceChange
}
// TODO: test
func (n *EvalReduceDiff) Eval(ctx EvalContext) (interface{}, error) {
in := *n.InChange
out := in.Simplify(n.Destroy)
if n.OutChange != nil {
*n.OutChange = out
}
if out.Action != in.Action {
if n.Destroy {
log.Printf("[TRACE] EvalReduceDiff: %s change simplified from %s to %s for destroy node", n.Addr, in.Action, out.Action)
} else {
log.Printf("[TRACE] EvalReduceDiff: %s change simplified from %s to %s for apply node", n.Addr, in.Action, out.Action)
}
}
return nil, nil
}
// EvalReadDiff is an EvalNode implementation that retrieves the planned
// change for a particular resource instance object.
type EvalReadDiff struct {
Addr addrs.ResourceInstance
DeposedKey states.DeposedKey
ProviderSchema **ProviderSchema
Change **plans.ResourceInstanceChange
}
func (n *EvalReadDiff) Eval(ctx EvalContext) (interface{}, error) {
providerSchema := *n.ProviderSchema
changes := ctx.Changes()
addr := n.Addr.Absolute(ctx.Path())
schema, _ := providerSchema.SchemaForResourceAddr(n.Addr.ContainingResource())
if schema == nil {
// Should be caught during validation, so we don't bother with a pretty error here
return nil, fmt.Errorf("provider does not support resource type %q", n.Addr.Resource.Type)
}
gen := states.CurrentGen
if n.DeposedKey != states.NotDeposed {
gen = n.DeposedKey
}
csrc := changes.GetResourceInstanceChange(addr, gen)
if csrc == nil {
log.Printf("[TRACE] EvalReadDiff: No planned change recorded for %s", addr)
return nil, nil
}
change, err := csrc.Decode(schema.ImpliedType())
if err != nil {
return nil, fmt.Errorf("failed to decode planned changes for %s: %s", addr, err)
}
if n.Change != nil {
*n.Change = change
}
log.Printf("[TRACE] EvalReadDiff: Read %s change from plan for %s", change.Action, addr)
return nil, nil
}
// EvalWriteDiff is an EvalNode implementation that saves a planned change
// for an instance object into the set of global planned changes.
type EvalWriteDiff struct {
Addr addrs.ResourceInstance
DeposedKey states.DeposedKey
ProviderSchema **ProviderSchema
Change **plans.ResourceInstanceChange
}
// TODO: test
func (n *EvalWriteDiff) Eval(ctx EvalContext) (interface{}, error) {
changes := ctx.Changes()
addr := n.Addr.Absolute(ctx.Path())
if n.Change == nil || *n.Change == nil {
// Caller sets nil to indicate that we need to remove a change from
// the set of changes.
gen := states.CurrentGen
if n.DeposedKey != states.NotDeposed {
gen = n.DeposedKey
}
changes.RemoveResourceInstanceChange(addr, gen)
return nil, nil
}
providerSchema := *n.ProviderSchema
change := *n.Change
if change.Addr.String() != addr.String() || change.DeposedKey != n.DeposedKey {
// Should never happen, and indicates a bug in the caller.
panic("inconsistent address and/or deposed key in EvalWriteDiff")
}
schema, _ := providerSchema.SchemaForResourceAddr(n.Addr.ContainingResource())
if schema == nil {
// Should be caught during validation, so we don't bother with a pretty error here
return nil, fmt.Errorf("provider does not support resource type %q", n.Addr.Resource.Type)
}
csrc, err := change.Encode(schema.ImpliedType())
if err != nil {
return nil, fmt.Errorf("failed to encode planned changes for %s: %s", addr, err)
}
changes.AppendResourceInstanceChange(csrc)
if n.DeposedKey == states.NotDeposed {
log.Printf("[TRACE] EvalWriteDiff: recorded %s change for %s", change.Action, addr)
} else {
log.Printf("[TRACE] EvalWriteDiff: recorded %s change for %s deposed object %s", change.Action, addr, n.DeposedKey)
}
return nil, nil
}